Berm hinge

ABSTRACT

A screed assembly includes a first screed plate having a working surface and an edge. A pivot body connected with the edge of the first plate has an axis and a bearing surface about the axis. A second screed plate has a working surface and an edge slidably disposed against the bearing surface. The second plate is movably connected with the first plate and pivotable about the axis to adjust the second working surface relative to the first working surface. A first hinge member connected with the first plate has an inner surface about the axis and spaced from the bearing surface. A second hinge member connected with the second plate has an inner surface slidably disposed against the bearing surface and an outer surface slidably disposed against the first member surface so as to be retained between the pivot body and the first member, thereby movably connecting the plates.

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/265,243, filed Jan. 31, 2001, and U.S. ProvisionalApplication No. 60/265,247, filed Jan. 31, 2001.

BACKGROUND OF THE INVENTION

[0002] The invention relates to road paving vehicles, and moreparticularly to screed plate assemblies used on road paving vehicles.

[0003] Paving vehicles or “pavers” are well known and basically functionto form a mat of paving material, such as asphalt or concrete, upon abase surface so as to construct a roadway, airport runway, parking lotor driveway. Pavers generally include a vehicle chassis or tractor thatcarries a bin/hopper for holding the paving material, a conveyor fortransporting the material from the hopper to the rear of the chassis andan auger for spreading the material laterally across the roadbed to forma material head behind the chassis. A screed assembly is towed from therear of the chassis and includes one or more upper frames and one ormore screed plates mounted beneath the frames. The screed assembly ispulled into a mass or “head” of paving material deposited off of therear of the chassis so that the screed plate(s) first “level” orestablish a desired material thickness and then partially compact thepaving material flowing under the plate. As a result, a strip or mat ofpaving material with a desired height or thickness is formed.

[0004] Certain screed assemblies include one or two screed plates thatmay each be pivoted or angled with respect to a longitudinal centerlineof the paving vehicle. These plates, referred to as “berm” plates, arelocated at each outer lateral or side end of the screed assembly and arepivotally connected to an inner, generally horizontal screed plate. Whenthe screed assembly is used to form a material mat, each berm plateforms an angled or sloped side section in the material mat, referred toas a berm. Such berms function as a curb for certain constructionprojects, for example, roadways built for residential areas. Certainberm-forming screed assemblies include a single plate and a frame thatmay be pivoted relative to another, primary screed frame to adjust theangle of the berm surface. Other berm-forming screed assemblies includean inner, generally horizontal screed plate and an outer plate thatpivotably attached to an outer end of the inner plate.

[0005] With berm-forming screed assemblies, it is important to ensurethat there is no gap or space between the adjacent ends of the outerberm plate and the inner horizontal plate. Such a gap creates anelevated stripe or ridge of material in the material mat extending alongthe intersection of berm section and the remaining section of the mat.Therefore, the screed assembly must be constructed such that acontinuous screed working surface extends laterally across the entirewidth of the screed assembly (i.e., laterally with respect to thedirection of paver travel). One approach to provide such a continuoussurface is to arrange the berm screed plate with the adjacent innerhorizontal screed plate such that a beveled edge of berm plate abutsagainst a mating beveled edge of the inner screed plate. The screedassembly is constructed such that the berm plate pivots with respect tothe inner screed plate by bending or folding along the line of contactbetween the edges of the two screed plates.

[0006] However, a deficiency with this arrangement results from the factthat contact between the two screed plates is established along thelowermost points of the beveled edges of the plates. As the screed andberm plate wear, a gap is formed between the adjacent plates when theselowermost points on the beveled edges are worn away by the abrasivecontact with the paving material. Once such a gap is created, pavingmaterial passes through the gap, causing an elongated, elevated stripeor ridge to be formed in the material mat, which must later beeliminated by appropriate repair operations (e.g., additional rolling).

[0007] In view of the above, it would be desirable to provide a bermscreed assembly in which such a gap is not formed by wearing of thescreed plates so as to thereby extend the effective product life of thescreed assembly.

SUMMARY OF THE INVENTION

[0008] In a first aspect, the present invention is a screed assemblycomprising a first screed plate having a working surface and a sideedge. A pivot body is connected with the side edge of the first screedplate and has an axis and an outer surface including a circumferentialbearing surface section spaced radially from and extending at leastpartially about the axis. Further, a second screed plate has a workingsurface and a side edge slidably disposed generally against the pivotbody bearing surface. The second screed plate is movably connected withat least one of the pivot body and the first screed plate such that thesecond screed plate is rotatably displaceable about the pivot body axisto adjustably position the second plate working surface with respect tothe first plate working surface.

[0009] In another aspect, the present invention is a hinge device for ascreed assembly of a paving vehicle, the screed having first and secondscreed plates. The hinge comprises a pivot body attached to the firstscreed plate and having an axis and an outer surface including agenerally circumferential bearing surface section extending at leastpartially about the axis. A first hinge member is connected with thefirst screed plate and has an inner circumferential surface disposedpartially about the block axis and spaced radially from the bearingsurface. Further, a second hinge member is connected with the secondscreed plate and has an inner circumferential surface slidably disposedgenerally against the bearing surface. The second hinge member also hasan outer circumferential surface spaced radially from the second hingemember inner surface and slidably disposed generally against the firsthinge member inner surface such that the second hinge member is slidablyretained between the pivot body and the first hinge member to movablyconnect the second screed plate with the first screed plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing summary, as well as the detailed description of thepreferred embodiments of the invention, will be better understood whenread in conjunction with the appended drawings. For the purpose ofillustrating the invention, there is shown in the drawings, which arediagrammatic, embodiments that are presently preferred. It should beunderstood, however, that the invention is not limited to the precisearrangements and instrumentalities shown. In the drawings:

[0011]FIG. 1 is a perspective view of a paving vehicle with a screedassembly and a hinge device in accordance with the present invention,shown performing a berm paving operation;

[0012]FIG. 2 is a more diagrammatic, broken-away, top plan view of thepaving vehicle;

[0013]FIG. 3 is as rear elevational view of the screed assembly and thehinge device;

[0014]FIG. 4 is a top perspective view of the screed assembly and hingedevice;

[0015]FIG. 5 is a broken-away, enlarged perspective view of the screedassembly and hinge device;

[0016]FIG. 6 is a broken-away, greatly enlarged side view of a firstscreed assembly half;

[0017]FIG. 7 is a broken-away, greatly enlarged side view of a secondscreed assembly half;

[0018]FIG. 8 is a broken-away, greatly enlarged side view of the hingedevice shown in a first position; and

[0019]FIG. 9 is a broken-away, greatly enlarged side view of the hingedevice shown in a second position.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Certain terminology is used in the following description forconvenience only and is not limiting. The words “upper”, “upward”, and“lower”, “downward” refer to directions toward and away from,respectively, a designated upper end of a screed assembly, a hingedevice, or a component of either the assembly or the device. The words“inner”, “inward” and “outer”, “outward” refer to directions toward andaway from, respectively, the geometric center of a hinge device or aspecific portion or component thereof, or toward and away from,respectively, a pivot body axis or a designated paving vehiclecenterline, the particular meaning intended being readily apparent fromthe context of the description. The terms “radial” and“radially-extending” refer to directions generally perpendicular to adesignated centerline or axis, and refer both to elements that areeither partially or completely oriented in radial direction. The terms“circumferential” and “circumferentially” refer to elements that areoriented so as to be partially or completely extending about adesignated centerline or axis. The terminology includes the wordsspecifically mentioned above, derivatives thereof, and words or similarimport.

[0021] Referring now to the drawings in detail, wherein like numbers areused to indicate like elements throughout, there is shown in FIGS. 1-9 apresently preferred embodiment of a hinge device 10 in accordance withthe present invention for a berm-forming screed assembly 12 used with apaving vehicle 1. The berm-forming or “berm” screed assembly 12 includesa first screed plate having a first working surface 15 and a secondscreed plate 16 having a second working surface 17. The hinge device 10basically comprises a pivot body 18 attached to the first screed plate14 and having a pivot axis 20 and an outer surface 22. The outer surface22 of the body 18 includes a generally circumferential bearing surfacesection 24 that is spaced radially from, and extends at least partiallyabout, the pivot axis 20. Further, the second screed plate 16 is movablyconnected with the pivot body 18 and/or with the first screed plate 16such that the second screed plate 16 is rotatably displaceable about thepivot body axis 20 to adjustably position the second plate workingsurface 17 with respect to the first plate working surface 15.

[0022] More specifically, the first screed plate 14 has an inner sideedge 26, the pivot body 18 being connected with the first plate sideedge 26 , and the second screed plate 16 has an inner side edge 28. Thesecond plate side edge 28 is slidably disposed generally against thepivot body bearing surface 24 such that the inner edge 28 of the secondplate 16 remains substantially in contact with the bearing surface 24when the second plate 16 rotatably displaces about the pivot axis 20.

[0023] Preferably, the hinge device 10 further comprises a first hingemember 30 connected with the first screed plate 14 and a second hingemember 32 connected with the second screed plate 16. The first hingemember 30 preferably has an inner circumferential surface 34 that isdisposed partially about the pivot axis 20 and is spaced radiallyoutwardly from the bearing 2+surface 24, as best shown in FIG. 6.Referring to FIGS. 8 and 9, the second hinge member 32 preferably has aninner circumferential surface 36 slidably disposed generally against thebearing surface 24 and an outer circumferential surface 38 spacedradially outwardly from the inner surface 36 and slidably disposedgenerally against the first hinge member inner surface 34. The secondhinge member 32 is thereby slidably retained between the pivot body 18and the first hinge member 30 so as to movably connect the second screedplate 16 with the first screed plate 14, as described in further detailbelow.

[0024] Referring now to FIGS. 1 and 2, the berm screed assembly 12 ofthe present invention is preferably connected with a main screedassembly 2 towed behind a paving vehicle or paver 1. The paving vehicle1 includes a chassis or tractor 3 having a front end 3 a, a rear end 3 band a longitudinal centerline 4 extending between the front and rearends 3 a, 3 b, respectively. Further, the main screed assembly 2includes a main or primary screed 5 and a pair of screed extensions 6,most preferably front-mounted, laterally movable or extendable screedextensions 6 (only one shown). Preferably, the main screed assembly 2includes two berm screed assemblies 12 of the present invention, eachmounted to the frame of a separate one of the two screed extensions 6,as discussed further below.

[0025] Each berm screed assembly 12 is substantially identicallyconstructed, but oppositely arranged with respect to the pavercenterline 4, such that only one screed assembly 12 will be described indetail herein. As best shown in FIG. 2, the screed assemblies 12 areeach connected with the paving vehicle 1 (i.e., through attachment tothe main screed assembly 2) such that the first screed plate 14 islocated inwardly of the second screed plate 16; in other words, thefirst and second screed plates 14 and 16, respectively, which each havea respective geometric center C₁ and C₂ (FIG. 2), are arranged such thatthe perpendicular distance between the second plate center C₂ and thevehicle centerline 4 is greater than the perpendicular distance betweenthe first plate center C₁ and the centerline 4. With this arrangement,the second screed plate 16 is adjustably positionable with respect tothe first screed plate 14 such that when the vehicle 1 is used toconstruct a mat of material M, an angled shoulder or berm B may beformed at the outer lateral or side edge E of the mat M.

[0026] The above description provides a basic disclosure of the primarycomponents and functionality of the hinge device 10 and berm screedassembly 12 of the present invention. To provide a more completeunderstanding of the present invention, each of these primarycomponents/functions is described in further detail below.

[0027] Referring now to FIGS. 4-6, the first screed plate 14 ispreferably formed as an elongated, generally rectangular plate having agenerally constant thickness t₁ (FIG. 6). The rectangular plate 40 has alower surface providing the first lower working surface 15 and has anopposing, generally flat upper surface 41. Further, the plate 40 hasinner and outer side edges 26 and 27, a front upwardly-bended leadingedge or nose 42 and a rear edge 43. Also, a pair of attachment blocks(FIG. 4) are spaced laterally apart and attached to the inner surface 42a of the nose 42, which are used to connect the first screed plate 14with a screed frame 13, as discussed below.

[0028] Referring to FIGS. 4, 5 and 7, the second screed plate 16 isgenerally formed as an elongated, generally rectangular plate having agenerally constant thickness t₂ (FIG. 7), each thickness t₁ and t₂preferably having about the same measured value, i.e., the two screedplates 14 and 16 are preferably of substantially equal thickness. Thesecond rectangular plate 46 has a lower surface providing the secondworking surface 17 and has an opposing, generally flat upper surface 47.Further, the plate 46 has inner and outer side edges 28 and 29, a frontupwardly-bended leading edge or nose 48 and a rear edge 49. Also, anattachment block 50 (FIG. 4) is attached to the inner surface 48 a ofthe nose 48 near the outer side edge 29 and is used to movably connectthe second screed plate 16 with the screed frame 13, as discussed below.

[0029] Further, the inner side edge 28 of the second screed plate isformed so as to have a concave, partially-circular contact surface 51with an inside radius R_(C) (FIG. 7) that is slightly larger than theoutside radius R_(P) of the pivot body 18. With this configuration, theedge contact surface 51 is juxtaposable against and slidablydisplaceable around or along the pivot bearing surface 24. In otherwords, substantially the entire concave contact surface 51 of the secondplate 16 remains in contact with and slides along the convex bearingsurface 24 of the pivot body 18 when the second screed plate 16 isrotatably displaced with respect to the first screed plate 14 (FIGS. 8and 9). However, if the pivot body 18 is alternatively connected withthe second screed plate 16 instead of with the first screed plate 14,the inner side edge 26 of the first screed plate 16 is preferably formedwith a surface similar to the concave edge contact surface 51 (structurenot depicted).

[0030] Although it is preferred that the screed plates 14, 16 aregenerally flat (except at the nose sections 42, 48), thin andrectangular, the screed plates 14 and/or 16 may be constructed havingany other appropriate or desired shape or structure as long as the hingedevice 10 and the screed assembly 12 are capable of functioningbasically as described herein. For example, either or both plates 14, 16may be square-shaped rather than rectangular, may have a substantialthickness (i.e., formed as a block rather than a plate), may have aseparately attached (rather than integrally formed) nose 42 or 48 orformed without a nose section, etc. The screed assembly 12 of thepresent invention is not limited to having screed plates 14, 16 with anyparticular structure and scope of the present invention encompasses allappropriate screed plate structures that enable the hinge device 10 andscreed assembly 12 to function generally as described herein.

[0031] Referring to FIGS. 4-6 and 9, the pivot body 18 is preferablyformed as an elongated, generally cylindrical bar 52 having a generallycontinuous circumferential outer surface 22 that completely encirclesthe pivot body axis 20. The bar 52 is preferably shaped as a solidcircular cylinder so as to have generally circular axial cross-sections(i.e., cross-sections spaced along the axis 20). Referring specificallyto FIG. 6, the bar 52 has an outside diameter D_(P) that is about twotimes, or twice as great, as the value of each thickness t₁ and t₂ ofthe two screed plates 14, 16, for reasons discussed below.

[0032] With the pivot body 18 formed as a cylindrical bar 52, thebearing surface 24 is thus provided by a section or portion of thecontinuous outer circumferential surface 22. The bearing surface 24 isthus convex and has a radius R_(P) that is substantially constant at allpoints or positions on the surface both radially about the body outercircumference and axially along the pivot axis 20. Preferably, the pivotbody 18 is disposed against the inner side edge 26 of the first screedplate 14 such that the axial length (not indicated) of the body 18extends along and parallel to the side edge 26. The pivot body 18preferably contacts the screed plate 14 along a top corner between theside edge 26 and the upper surface 41, such that a semi-circular upperhalf of the pivot body 18 is generally located above the plate uppersurface.

[0033] When the bar 52 is positioned as described above, a wedge-shapedrecess 56 (FIG. 6) is defined between the bar 52 and the plate side edge42. Preferably, the recess 56 is filled with weldment material 57 (FIGS.8 and 9) to fixedly attach the pivot body 18 to the first screed plate14, the weldment material 57 being applied such to form a continuoussurface 58 connecting the pivot outer surface 22 with the first screedworking surface 15. Alternatively, the inner edge 26 of the first plate14 may be formed with a concave surface (not depicted) similar to theinner edge 28 of the second plate 16, against which surface the pivotbody 18 may be closely disposed.

[0034] Although the pivot body 18 is preferably a solid, circularcylindrical bar 52 as described above, the pivot body 18 may be formedwith any appropriate shape or structure, as long as a portion of thebody 18 provides the convex outer circumferential bearing surface 24 asdescribed herein. For example, the pivot body 18 may be tubular with acircular, semi-circular or complex-shaped outer surface (none shown).Further for example, the pivot body 18 may be formed as a block, bar ortube or an assembly of attached together bars/plates, having any desiredshape, such as circular, partially-circular, partially-rectangularand/or prismatic (no alternatives shown), as long as a portion of theparticular body's outer surface provides the outer circumferentialbearing surface 24 as described herein.

[0035] As yet another example, the pivot body 18 may be integrallyformed with one of the two screed plates 14 or 16 (structure notdepicted), such as for example, by forming the particular plate 14, 16as a casting having an edge portion providing the pivot body 18 or as astamping with a side edge formed or bended to provide the pivot body 18.The present invention encompasses all desired or appropriateconstructions of the pivot body 18 that includes a convex outercircumferential bearing surface 24 and enable the hinge device 10 tofunction as generally described herein.

[0036] Referring to FIGS. 4-6, 8 and 9, the first hinge member 30 ispreferably formed as a generally arcuate plate 60 having a firstlengthwise side edge or end 62, an opposing second lengthwise side end64, and opposing front and rear widthwise ends 65 (only rear end shown).Preferably, the hinge plate 60 is generally formed as a rectangularplate bended lengthwise, shaped generally similar to anaxially-extending portion of a circular tube, as best shown in FIG. 5,so as to have a concave lower surface providing the innercircumferential surface 34 of the first hinge member 30. Further, thehinge plate 60 is formed such that the inner surface 34 has an insideradius R_(I1) (FIG. 6) that is slightly larger than an outside radiusR_(O2) (FIG. 7) of the second hinge member 32, for reasons discussedbelow.

[0037] Referring particularly to FIG. 6, preferably, the first hingemember 30 is connected with the first screed plate 14 by attaching thehinge plate first side end 62 to the screed upper surface 41 at aposition proximal to the screed inner edge 26. The first hinge plate 60extends over the plate edge 26 such that hinge plate second side end 64is spaced horizontally beyond the screed plate inner edge 26 and is“free” or unattached. Further, the hinge plate 60 is positioned withrespect to the pivot body 18 such that the concave plate inner surface34 is spaced radially outwardly from the convex outer bearing surface 24of the pivot body 18 by a radial distance d_(R), as indicated in FIG. 6.The radial distance d_(R) has a value that is slightly greater or largerthan the thickness t₂ of the second screed plate 16. Further, the firsthinge plate 60 is preferably fixedly attached to the first screed plate14, such as by welding, braising, riveting, etc., but may alternativelybe removably attached by appropriate means, such as by threadedfasteners or separate mounting brackets (none depicted).

[0038] Still referring to FIG. 6, by spacing the first hinge plate fromthe pivot body 18 in the above-described manner, a curved or arcuateretention gap 66 is formed between the facing circumferential surfaces24, 34 of the pivot body 18 and the first hinge member 30, respectively.The retention gap 66 is sized and shaped to receive a substantialportion of the second hinge member 32, as discussed in further detailbelow. With the pivot body 18 and the first hinge member 30 attached tothe first screed plate 14 in the manner described above, a first screedassembly half 68 is formed, which is movably connected together with asecond screed assembly half 78, as discussed below.

[0039] Referring now to FIGS. 5 and 7-9, the second hinge member 32 ispreferably formed as a generally arcuate plate 70 having a firstlengthwise side end 72, an opposing second lengthwise side end 74 andopposing front and rear widthwise ends 75 (only rear end shown).Preferably, the second hinge plate 70 is formed as a rectangular platebended lengthwise so as to be shaped similar to an axially-extendingportion of a circular tube (FIG. 5), and is thus shaped similarly to thefirst hinge plate 60. More specifically, the second hinge plate 70 has aconcave lower surface providing the inner circumferential surface 36 ofthe second hinge member 32 and a convex upper surface providing theouter circumferential surface 38 of the second hinge member 32, as bestshown in FIG. 7.

[0040] The second hinge plate 70 is constructed such that the concaveinner circumferential surface 36 has a inside radius R_(I2) (FIG. 7)that is slightly larger or greater than the outside radius R_(P) of thepivot body outer bearing surface 24. Further, the convex outer surface38 of the second hinge plate 70 has an outside radius R_(O2) that isslightly smaller or lesser than the inside radius R_(I1), of the firsthinge member inner surface 34. With this structure, the second hingeplate 70 is configured to be inserted into the retention gap 66 betweenthe first hinge plate 60 and the pivot body 18, as discussed below.

[0041] Referring particularly to FIG. 7, preferably, the second hingemember 32 is connected with the second screed plate 16 by attaching thehinge plate first side end 72 to the screed plate upper surface 47 at aposition adjacent to the screed plate inner side end 28. Morespecifically, the second hinge plate 70 is located such that a loweredge 36 a of the hinge plate inner circumferential surface 36 issubstantially aligned with the upper edge 51 a of the screed platecontact surface 51. As such, the two circumferential surfaces 36, 51share a common centerline 77 (end view only) (FIG. 7) and form agenerally continuous inner circumferential surface extending between thehinge plate free end 74 and the screed plate lower edge 51 b. Further,as with the first hinge plate 60, the second hinge plate 70 ispreferably fixedly attached to the second screed plate 16, but mayalternatively be removably attached by appropriate means.

[0042] Further, the second hinge plate 70 extends beyond the secondscreed plate edge 51 such that the hinge second side end is spacedhorizontally from the screed plate inner edge 28 and is “free” orunattached. With the second hinge member 32 attached to the secondscreed plate 16 in the manner described herein, a second screed assemblyhalf 78 is formed, which is movably connected together with the firstscreed assembly half in the following manner.

[0043] Referring now to FIGS. 5, 6, 8 and 9, the hinge device 10 isassembled together, so as to movably connect the first and second screedplates 14, 16, in the following manner. First, the second screed plateassembly 78 is positioned with respect to the first screed plateassembly 68 such that the inner surface 36 of the second hinge plate 70is disposed on a rear portion of the outer surface 22 of the pivot body18, with the second hinge plate 70 being rearwardly of and axiallyadjacent to the first hinge plate 60. More specifically, the front end75 of the second hinge plate 70 is positioned at the rear opening 66 ainto the retention gap 66 so as to be adjacent to, but spaced radiallyinwardly of, the rear end 65 of the first plate 60 (FIG. 6).

[0044] Then, the entire second plate assembly 78 is displaced in afrontward direction along the pivot body axis 20 such that the secondhinge plate 70 slides along the pivot body outer surface 22, enters andbecomes increasingly disposed within the gap 66, until the second hingeplate rear end 75 is generally radially aligned with the first hingeplate rear end 65. Further, the opposing front and rear ends 75 (onlyrear end shown) of the second hinge plate 70 are spaced apart along thepivot body axis and are generally radially aligned with the respectivefront and rear ends 65 (only rear shown) of the first hinge plate 60, asbest shown in FIG. 5. When the second hinge plate 70 is disposed withinthe retention gap 66 as described, a substantial portion of the secondhinge plate 70 is disposed or “sandwiched” radially between the firsthinge plate 60 and the pivot body 18. More specifically, the lowerconcave inner circumferential surface 36 of the second hinge plate 70 isdisposed substantially against the convex pivot body bearing surface 24and the upper convex outer circumferential surface 38 of the secondhinge plate 70 is disposed substantially against the concave first plateinner circumferential surface 34, as best shown in FIGS. 8 and 9.

[0045] Referring to FIGS. 4 and 5, preferably, when the second hingeplate 70 is disposed within the retention gap 66 as described, first andsecond retainer blocks 80, 82, respectively, are each connected with thefirst screed plate 14 and located so as to be disposed proximal to aseparate one of the front and rear ends 65 of the second hinge member34. The second hinge plate 70 is thereby sandwiched axially between thetwo blocks 80 and 82, such that the retainer blocks 80, 82 limit lineardisplacement of the second hinge member 32 in directions generally alongthe pivot body axis 20. Preferably, each retainer blocks 80, 82 isformed as a generally flat, rectangular prism, the second block 82 beinglarger and having a cut-out or notch 81 providing a stop portion 83, asdiscussed below. The first retainer block 80 is fixedly attached to thenose 42 so as to extend generally horizontally across the pivot axis 20and abuts against the front end (not shown) the second hinge plate 70.The second retainer block 82 is removably attached to the first screedplate upper surface 41 such that the stop portion 83 extends generallyhorizontally over the pivot axis 20 and abuts against the rear end 75 ofthe second hinge plate 70, thereby “trapping” the second hinge plate 70between the two retainer blocks 80, 82.

[0046] With the first and second screed plate assemblies 68, 78 and thetwo retainer blocks 80, 82 assembled as described, the second hingemember 32 is slidably retained between the pivot body 18 and the firsthinge member 30 to movably or rotatably connect the second screed plate16 with the first screed plate 14. The first hinge plate 60 always atleast partially overlaps the second hinge plate 70 when the second plate70 is rotatably displaced about the pivot axis 20. As such, when thesecond screed plate 16 is rotatably displaced or pivoted about the pivotaxis 20, the second hinge plate 70 slides beneath the first hinge plate60 such that the free end 74 of the second plate 70 moves generallybetween a first position Pi (FIG. 7) more proximal to the free end 64 ofthe first hinge plate 60 and a second position P₂ (FIG. 8) more proximalto the upper surface of the first screed plate 14.

[0047] Referring to FIGS. 1-3, the screed assembly 12 preferably furtherincludes a screed frame 13 disposed generally above the first and secondscreed plates 14, 16, respectively. The screed frame 13 is preferablyformed as a generally rectangular, box-like assembly of plates and has alower end 87 to which the first screed plate 16 is removably attached.Preferably, the screed frame 13 forms part of a screed extension 6connected with a main screed 5, and most preferably, a laterally movableor extendible screed extension 6. Alternatively, the screed frame 13 maybe fixedly attached to a lateral end or side of the main screed 5 or maybe formed as an integral end portion of the main screed 5 (neithershown).

[0048] Referring specifically to FIG. 3, the berm screed assembly alsopreferably includes a connective member 88 having a first end 89connected with the frame 13 and a second end 90 connected with thesecond screed plate 16. The member second end 90 is linearlydisplaceable with respect to the member first end 89 so as to cause thesecond screed plate 16 to rotatably displace about the pivot body axis20. Preferably, the connective member 88 is formed as a hydrauliccylinder including a cylinder body 91, with an outer end of the cylinderbody 91 providing the connective member first end 89, and an extendablerod 92, the free end of the rod 91 providing the connective membersecond end 90. The end of rod 92 is preferably pivotably attached to thesecond screed plate attachment member 50, most preferably by a pin shaft(not indicated), to connect the rod 92 with the second screed plate 16.

[0049] With a connective member 88 constructed as a hydraulic cylinder,fluid flow within the cylinder body 90 causes the rod to extend andretract, which thereby moves or displaces the attached section of thesecond screed plate 16. The displacement of the attached section of thesecond screed plate causes the entire second plate 16 to rotatablydisplace about the pivot axis 20, while the contact surface 51 of thesecond plate 16 slides along or about the bearing surface 24 of thepivot body 18. Alternatively, the hydraulic cylinder 88 may be invertedsuch that the rod 91 is attached to the frame 13 and the cylinder body90 is attached to the second plate 16. Further, the connective member 88may alternatively be provided by any other appropriate connectivedevice/assembly having a second end 89 displaceable with respect to afirst end 90, such as for example, a threaded rod and nut/threaded holearrangement, a cable and pulley device, a rack and pinion structure, ora linkage mechanism.

[0050] Preferably, the screed plates 14 and 16, the hinge plates and 70,and the screed frame 13 are each preferably fabricated from plates oflow carbon steel that are hardened by appropriate means at surfaceslikely to experience wear, such as for example, the working surfaces 15and 17. The pivot body is preferably cut from an appropriate length of acircular rod of low carbon steel, with the outer surface 22 hardened byappropriate means. Further, the connective member 88 is preferably acommercially available hydraulic cylinder. However, it is within thescope of the present invention to fabricate any of the components of thehinge device 10 and the screed assembly 12 from any other appropriatematerial and in any other appropriate manufacturing process.

[0051] Referring now to FIGS. 1 and 2, the screed assembly 12 of thepresent invention may be used to either to form a standard orconventional mat of material M (not shown) or a material mat M with one(FIG. 1) or two (FIG. 2) side berm sections B. The different operatingmodes of the berm screed assembly 12 are provided by the capability ofmoving or adjusting the second screed plate 16, and thus the entiresecond screed assembly 78, between first and second positions P₁ (FIG.8) and P₂ (FIG. 9), respectively, as indicated in the drawings by“tracking” the position of the second end 74 of the second hinge plate70 for reasons of convenience only. In the first position P₁, shown inFIG. 8, the second plate working surface 17 and the first plate workingsurface 15 are generally disposed in a common horizontal plane (notindicated). In other words, the screed plates 14, 16 are generallyaligned such that an angle β (FIG. 8) between the plates 14, 16 issubstantially zero degrees. With the two screed plates 14, 16 arrangedin this manner, the berm screed assembly 12 forms a material mat Mhaving a generally horizontal upper surface S across the entire lateralwidth of the screed assembly 12.

[0052] In the second position P₂, as shown in FIG. 8, the second screedplate 16 is angled with respect to the first screed plate such that thesecond working surface 17 is disposed at a vertical angle β with respectto the first working surface 15. More specifically, the first workingsurface 15 is disposed in a generally horizontal plane and the secondworking surface 17 is disposed in an angled plane (i.e., at angle β)that extends upwardly and outwardly from the inner edge 28 of the secondscreed plate 16. Although only two positions P₁ and P₂ are depicted, thesecond screed plate 14 is positionable at any desired position betweenthe depicted first and second positions P₁, P₂, which are the presentlypreferred limits of the displacement of the second screed plate 16, suchthat the angle β may have any value between about 0° (FIG. 7) and about45° (FIG. 8). Further, in the second position P₂, the screed plate 16may be at a greater angle β with respect to the first plate 14 than aspresently preferred, such as for example, so that the angle β has avalue of about 60°. Furthermore, if desired, the screed assembly 12 mayalternatively be constructed such that the second screed plate 16 iscapable of being negatively sloped or angled with respect to the firstscreed plate 14 (i.e., sloped in a direction downwardly and outwardlyfrom the first plate 14).

[0053] When the two screed plates 14, 16 are positioned with the angle βbeing greater than 0° (as shown in FIG. 9), a continuous screed workingsurface is provided by the first and second plate working surfaces 15,17, respectively, and a portion of the pivot body outer surface 22between the inner side edge 26 of the first screed plate 14 and theinner side edge 28 of the second screed plate 16. With thisconfiguration, the screed assembly 12 forms the material mat M with twosections, a first angled berm section B and a remaining, generallyhorizontal section R, as shown in FIGS. 1 and 2. More specifically, theangled berm section B is located at the lateral side or edge of thematerial mat M and has an upper surface S_(A) disposed at about thevertical angle β with respect to an upper surface S_(R) of the remainingsection R of the material mat M, as indicated in FIG. 1. In thepreferred application where the paving vehicle 1 has two berm-formingscreed assemblies 12, the two screed assemblies may be used to form asingle berm B at either one of the side edges E of the material mat M(FIG. 1), two berms B each located at a separate one of the two edges Eof the material mat M (FIG. 2), or a conventional material mat M withoutany berms (not shown).

[0054] To change between the basic operating modes, or to adjust theberm angle β between the screed working surfaces 15 and 17, the secondscreed plate 16 is rotatably displaced about the pivot body axis 20 byuse of the hydraulic cylinder connective member 88, as described indetail above. Preferably, the screed operator adjusts the position ofthe second screed plate 16 through a controller (not shown) configuredto automatically operate the preferred hydraulic cylinder 88. Further,when the paving vehicle 1 has two screed assemblies 12 as preferred, theoperator preferably independently operates each of the two cylinders 88of the two screed assemblies 12.

[0055] As with all screed plates, after a period of use, the material ofthe first and second screed plates 14 and 16 will, to a certain extent,wear or abrade away such that the thickness t₁ and t₂ of each plate 14,16, respectively, decreases. As the screed plates 14 and 16 wear away,the bottom or lower portion 18 a of the pivot body 18 also wears away bya similar amount of material thickness. Specifically, as the portion ofthe second plate 16 proximal to the plate inner edge 28 wears away, thelowermost edge 51 b of the contact surface 51 progressively “moves”upwardly about the outer circumference of the pivot body 18, but stillremains in contact with an adjacent portion of the pivot body 18 (thematerial of which is also worn away with the adjacent portions of theplate 16). As such, no gap is ever formed between the inner edge 26 ofthe first screed plate 14 and the inner edge 28 of the second screedplate 16. Thus, the hinge device 10 enables the screed assembly 12 ofthe present invention to have a substantially continuous working surfaceacross the lateral width of the two screed plates 14 and 16 throughout anormal product life of the screed plates 14, 16.

[0056] It will be appreciated by those skilled in the art that changescould be made to the embodiments described above without departing fromthe broad inventive concept thereof. It is understood, therefore, thatthis invention is not limited to the particular embodiments disclosed,but it is intended to cover modifications within the spirit and scope ofthe present invention as defined by the appended claims.

We claim:
 1. A screed assembly comprising: a first screed plate having aworking surface and a side edge; a pivot body connected with the sideedge of the first screed plate and having an axis and an outer surfaceincluding a circumferential bearing surface section spaced radially fromand extending at least partially about the axis; and a second screedplate having a working surface and a side edge slidably disposedgenerally against the pivot body bearing surface, the second screedplate being movably connected with at least one of the pivot body andthe first screed plate such that the second screed plate is rotatablydisplaceable about the pivot body axis to adjustably position the secondplate working surface with respect to the first plate working surface.2. The screed assembly as recited in claim 1 wherein the edge of thesecond plate remains substantially in contact with the bearing surfacewhen the second plate rotatably displaces about the pivot body axis. 3.The screed assembly as recited in claim 1 wherein the first plateworking surface, the second plate working surface and a portion of thepivot block outer surface extending between the edge of the first plateand the edge of the second plate form a generally continues screedworking surface.
 4. The screed assembly as recited in claim 1 whereinthe second plate is movable between a first position where the secondplate working surface and the first plate working surface are generallydisposed in a common horizontal plane and a second position where thesecond plate working surface is disposed at a vertical angle withrespect to the first plate working surface.
 5. The screed assembly asrecited in claim 1 wherein the pivot body is formed as a generallycylindrical bar having a generally continuous circumferential outersurface encircling the pivot body axis.
 6. The screed assembly asrecited in claim 1 further comprising: a first hinge member connectedwith the first screed plate and having a circumferential inner surfacespaced radially from the pivot body outer surface; and a second hingemember connected with the second screed plate and having an innercircumferential surface disposed generally against the pivot body outersurface and an outer circumferential surface disposed generally againstthe first hinge member inner surface such that the second hinge memberis retained at least partially between the first hinge member and thepivot body to movably connect the second screed plate with the firstscreed plate.
 7. The screed assembly as recited in claim 6 wherein: thefirst hinge member is formed as a generally arcuate plate having a firstend connected with the first screed plate and a second, opposing freeend; and the second hinge member is formed as a generally arcuate platehaving a first end connected with the second screed plate and a second,opposing free end, the first hinge plate at least partially overlappingthe second hinge plate such that the free end of the second hinge plateis displaceable generally between a first position proximal to the freeend of the first hinge plate and a second position proximal to the firstscreed plate.
 8. The screed assembly as recited in claim 6 wherein: thesecond hinge member has opposing ends spaced apart along the pivot bodyaxis; and the screed assembly further comprises first and secondretainer blocks each connected with the first screed plate and disposedproximal to a separate one of the ends of the second hinge member so asto limit linear displacement of the second hinge member in directionsgenerally along the pivot body axis.
 9. The screed assembly as recitedin claim 1 further comprising: a screed frame disposed generally abovethe first and second screed plates and having a lower end, the firstscreed plate being removably attached to the lower end of the frame; anda connective member having a first end connected with the frame and asecond end connected with the second plate, the connective member secondend being displaceable with respect to the connective member first endso as to rotatably displace the second screed plate about the pivot bodyaxis.
 10. The screed assembly as recited in claim 1 in combination witha paving vehicle for forming a mat of material.
 11. The screed assemblyas recited in claim 10 wherein: the paving vehicle has a front end, arear end and a longitudinal centerline extending between the front andrear ends; the first and second screed plates each have a geometriccenter and the screed assembly is connected with the paving vehicle suchthat the distance between the second plate center and the vehiclecenterline is greater than a distance between the first plate center andthe centerline; and the second screed plate is adjustably positionablewith respect to the first screed plate such that when the vehicle formsa mat of material, an angled shoulder is formed at an outer edge of themat.
 12. A hinge device for a screed assembly of a paving vehicle, thescreed having first and second screed plates, the hinge comprising: apivot body attached to the first screed plate and having an axis and anouter surface including a generally circumferential bearing surfacesection extending at least partially about the axis; a first hingemember connected with the first screed plate and having an innercircumferential surface disposed partially about the block axis andspaced radially from the bearing surface; and a second hinge memberconnected with the second screed plate and having an innercircumferential surface slidably disposed generally against the bearingsurface and an outer circumferential surface spaced radially from thesecond hinge member inner surface and slidably disposed generallyagainst the first hinge member inner surface such that the second hingemember is slidably retained between the pivot body and the first hingemember to movably connect the second screed plate with the first screedplate.
 13. The hinge device as recited in claim 12 wherein: the firstscreed plate has a working surface and a side edge, the pivot body beingattached to the first plate side edge; and a second screed plate has aworking surface and a side edge slidably disposed generally against thepivot body bearing surface, the second screed plate being rotatablydisplaceable about the pivot body axis to adjustably position the secondplate working surface with respect to the first plate working surface.14. The hinge device as recited in claim 13 wherein the edge of thesecond plate remains substantially in contact with the bearing surfacewhen the second plate rotatably displaces about the pivot body axis. 15.The hinge device as recited in claim 12 wherein the pivot body is formedof a generally cylindrical bar having a generally continuouscircumferential outer surface encircling the pivot body axis.
 16. Thehinge device as recited in claim 12 wherein: the first hinge member isformed as a generally arcuate plate having a first end connected withthe first screed plate and a second, opposing free end; and the secondhinge member is formed as a generally arcuate plate having a first endconnected with the second screed plate and a second, opposing free end,the first hinge plate at least partially overlapping the second hingeplate such that the free end of the second hinge plate is displaceablegenerally between a first position proximal to the free end of the firsthinge plate and a second position proximal to the first screed plate.17. The hinge device as recited in claim 12 wherein: the second hingemember has opposing ends spaced apart along the pivot body axis; and thehinge device further comprises first and second retainer blocks eachconnected with the first screed plate and disposed proximal to aseparate one of the ends of the second hinge member so as to limitlinear displacement of the second hinge member in directions generallyalong the pivot body axis.